Direct observation of photomagnetization of the ferromagnet CdCr2Se4 by circularly polarized light
Genkin G. M. , Nozdrin Yu. N. , Tokman I. D. , Shastin V. N.
A photomagnetization AM has been observed in a polydomain Cd^ Ag^ Cr2Se4 crystal (x = 0.02%) at Τ = 77 К as the crystal is bombarded with a circularly polarized laser beam (Я = 1.06 μ m, power density Ρ < 10 W/cm2). The value of AM was measured as a function for various polarizations and power densities of the laser beam and for various strengths of magnetic field H0. The results show that AM is maximized by circularly polarized light; when the polarization rotation direction is reversed, AM changes sign. For linear polarization, the results yield AM — 0. For external magnetic fields near the saturation level, the results reveal AM = 0. The results are explained in terms of a mechanism involving a change in the domain structure.